Search Results - "Nielsen, K.L."

Cohesive traction–separation laws for tearing of ductile metal plates by Nielsen, K.L., Hutchinson, J.W.

“…The failure process ahead of a mode I crack advancing in a ductile thin metal plate or sheet produces plastic dissipation through a sequence of deformation…”
Get full text

On modeling micro-structural evolution using a higher order strain gradient continuum theory by El-Naaman, S.A., Nielsen, K.L., Niordson, C.F.

“…Published experimental measurements on deformed metal crystals show distinct pattern formation, in which dislocations are arranged in wall and cell structures…”
Get full text

Strain gradient effects in periodic flat punch indenting at small scales by Nielsen, K.L., Niordson, C.F., Hutchinson, J.W.

“…Experiments on soft polycrystalline aluminum have yielded evidence that, besides the required punch load, both the size and shape of imprinted features are…”
Get full text

Steady-state numerical modeling of size effects in micron scale wire drawing by Juul, K.J., Nielsen, K.L., Niordson, C.F.

“…Wire drawing processes at the micron scale have received increased interest as micro wires are increasingly required in electrical components. It is…”
Get full text

Controlled atmosphere storage at high CO₂ and low O₂ levels affects stomatal conductance and influence root formation in kalanchoe cuttings by Bredmose, N.B, Nielsen, K.L

“…Since the response of cuttings to raised CO₂ concentration is not documented, controlled atmosphere (CA) storage of kalanchoe cuttings at combinations of high…”
Get full text

Dynamic size effects across the scales: Localization in round notched bars by Andersen, R.G., Nielsen, K.L.

“…The strengthening and hardening of metals increase with diminishing size due to plastic strain gradient accompanied by Geometrically Necessary Dislocations…”
Get full text

Computational rate-independent strain gradient crystal plasticity by Nielsen, K.L.

“…Size effects in metal plasticity are widely accepted, and different theoretical approaches to handle the phenomenon are developing in the literature. The…”
Get full text

A micro-mechanics based extension of the GTN continuum model accounting for random void distributions by Holte, I., Nielsen, K.L., Martínez-Pañeda, E., Niordson, C.F.

“…Randomness in the void distribution within a ductile metal complicates quantitative modeling of damage following the void growth to coalescence failure…”
Get full text

Void size, shape, and orientation effects in shear-dominated void coalescence across scales by Xiao, Y., Niordson, C.F., Nielsen, K.L.

“…In a stress state dominated by shear, pre-existing voids rotate, elongate, and close up to form micro-cracks, which interact through void coalescence and…”
Get full text

Gradient strengthening effects in mode I tearing of ductile plate at the engineering scale by Vishwakarma, V., Nielsen, K.L.

“…The present study aims to quantify the influence of void size effect on crack initiation and growth in mode I tearing of large ductile plates. Specifically,…”
Get full text

Effect of damage-related microstructural parameters on plate tearing at steady state by Tekog̃lu, C., Nielsen, K.L.

“…The tearing of ductile metal plates can take place in three distinctly different modes: cup-cup, cup-cone, and crack slanting, but they are often observed in…”
Get full text

Growing media for organic tomato plantlet production by Nielsen, K.L, Thorup-Kristensen, K

Get full text

A numerical basis for strain-gradient plasticity theory: Rate-independent and rate-dependent formulations by Nielsen, K.L., Niordson, C.F.

“…A numerical model formulation of the higher order flow theory (rate-independent) by Fleck and Willis [2009. A mathematical basis for strain-gradient plasticity…”
Get full text

Parameter window for assisted crack tip flipping: Studied by a shear extended Gurson model by Nielsen, K.L., Felter, C.L.

“…Assisted flipping of a slant mode I dominated tearing crack, where the crack tip flipping mechanism is made to engage by imposing a slight mode III, has…”
Get full text

Fundamental differences between plane strain bending and far-field plane strain tension in ductile plate failure by Andersen, R.G., Londono, J.G., Woelke, P.B., Nielsen, K.L.

“…The objective of this paper is to investigate the ductile fracture behavior of thin metal plates under nominally plane strain conditions, with an emphasis on…”
Get full text

Micro-mechanics based cohesive zone modeling of full scale ductile plate tearing: From initiation to steady-state by Andersen, R.G., Felter, C.L., Nielsen, K.L.

“…Ductile plate tearing, where the crack propagates multiple plate thicknesses, is targeted by the micro-mechanics based Gurson-Tvergaard-Needleman (GTN) model…”
Get full text

Investigation of a gradient enriched Gurson-Tvergaard model for porous strain hardening materials by Holte, I., Niordson, C.F., Nielsen, K.L., Tvergaard, V.

“…Size effects in a strain hardening porous solid are investigated using the Gurson-Tvergaard (GT) model enriched by a constitutive length parameter, as proposed…”
Get full text

A finite strain framework for steady-state problems: Hyperelasto-viscoplasticity by Juul, K.J., Nielsen, K.L., Niordson, C.F.

“…A numerical framework for analyzing steady-state elastic–plastic material deformation at finite strains is developed and demonstrated in the present work. The…”
Get full text

A finite strain FE-Implementation of the Fleck-Willis gradient theory: Rate-independent versus visco-plastic formulation by Nielsen, K.L., Niordson, C.F.

“…This paper presents a numerical basis for finite strain analysis using the higher order flow theory by Fleck and Willis [2009, A mathematical basis for…”
Get full text

An investigation of back stress formulations under cyclic loading by El-Naaman, S.A., Nielsen, K.L., Niordson, C.F.

“…•Numerical investigation of back stress formulations in simple shear cyclic loading.•Comparison of thermodynamically consistent approach to a phenomenological…”
Get full text